diff --git a/contrib/intarray/_int.h b/contrib/intarray/_int.h
index b689eb7ded..f03fdf9add 100644
--- a/contrib/intarray/_int.h
+++ b/contrib/intarray/_int.h
@@ -85,12 +85,6 @@ typedef struct
 
 #define GETSIGN(x)		( (BITVECP)( (char*)x+GTHDRSIZE ) )
 
-/*
- * types for functions
- */
-typedef ArrayType *(*formarray) (ArrayType *, ArrayType *);
-typedef void (*formfloat) (ArrayType *, float *);
-
 /*
  * useful functions
  */
diff --git a/src/backend/access/nbtree/README b/src/backend/access/nbtree/README
index c5b0a30e4e..3d01b7854d 100644
--- a/src/backend/access/nbtree/README
+++ b/src/backend/access/nbtree/README
@@ -457,7 +457,7 @@ right sibling's left-link --- followed by a second WAL entry for the
 insertion on the parent level (which might itself be a page split, requiring
 an additional insertion above that, etc).
 
-For a root split, the followon WAL entry is a "new root" entry rather than
+For a root split, the follow-on WAL entry is a "new root" entry rather than
 an "insertion" entry, but details are otherwise much the same.
 
 Because splitting involves multiple atomic actions, it's possible that the
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 43627ab8f4..9238fbe98d 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -716,7 +716,7 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
 
 	namestrcpy(&attrtypes[attnum]->attname, name);
 	elog(DEBUG4, "column %s %s", NameStr(attrtypes[attnum]->attname), type);
-	attrtypes[attnum]->attnum = attnum + 1; /* fillatt */
+	attrtypes[attnum]->attnum = attnum + 1;
 
 	typeoid = gettype(type);
 
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 6b8ef40599..cb4ab4b21e 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -882,7 +882,7 @@ process_ordered_aggregate_multi(AggState *aggstate,
  * This function handles only one grouping set (already set in
  * aggstate->current_set).
  *
- * The finalfunction will be run, and the result delivered, in the
+ * The finalfn will be run, and the result delivered, in the
  * output-tuple context; caller's CurrentMemoryContext does not matter.
  *
  * The finalfn uses the state as set in the transno. This also might be
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 7332e6b590..65c53e18fa 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -438,7 +438,7 @@ static void PinBuffer_Locked(BufferDesc *buf);
 static void UnpinBuffer(BufferDesc *buf, bool fixOwner);
 static void BufferSync(int flags);
 static uint32 WaitBufHdrUnlocked(BufferDesc *buf);
-static int	SyncOneBuffer(int buf_id, bool skip_recently_used, WritebackContext *flush_context);
+static int	SyncOneBuffer(int buf_id, bool skip_recently_used, WritebackContext *wb_context);
 static void WaitIO(BufferDesc *buf);
 static bool StartBufferIO(BufferDesc *buf, bool forInput);
 static void TerminateBufferIO(BufferDesc *buf, bool clear_dirty,
@@ -2346,7 +2346,7 @@ BgBufferSync(WritebackContext *wb_context)
  *	BUF_REUSABLE: buffer is available for replacement, ie, it has
  *		pin count 0 and usage count 0.
  *
- * (BUF_WRITTEN could be set in error if FlushBuffers finds the buffer clean
+ * (BUF_WRITTEN could be set if FlushBuffer finds the buffer clean
  * after locking it, but we don't care all that much.)
  *
  * Note: caller must have done ResourceOwnerEnlargeBuffers.
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 7b49802b4e..315c74c745 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -897,7 +897,7 @@ count_usable_fds(int max_to_probe, int *usable_fds, int *already_open)
 
 /*
  * set_max_safe_fds
- *		Determine number of filedescriptors that fd.c is allowed to use
+ *		Determine number of file descriptors that fd.c is allowed to use
  */
 void
 set_max_safe_fds(void)
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
index 565c3ac439..0e2bfc9f83 100644
--- a/src/backend/storage/lmgr/predicate.c
+++ b/src/backend/storage/lmgr/predicate.c
@@ -4820,7 +4820,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
  *
  * If a dangerous structure is found, the pivot (the near conflict) is
  * marked for death, because rolling back another transaction might mean
- * that we flail without ever making progress.  This transaction is
+ * that we fail without ever making progress.  This transaction is
  * committing writes, so letting it commit ensures progress.  If we
  * canceled the far conflict, it might immediately fail again on retry.
  */
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index c3c2ea1473..ccf2153fac 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -637,9 +637,6 @@ typedef struct _extensionMemberId
 	ExtensionInfo *ext;			/* owning extension */
 } ExtensionMemberId;
 
-/* global decls */
-extern bool force_quotes;		/* double-quotes for identifiers flag */
-
 /* placeholders for comment starting and ending delimiters */
 extern char g_comment_start[10];
 extern char g_comment_end[10];
diff --git a/src/interfaces/ecpg/compatlib/informix.c b/src/interfaces/ecpg/compatlib/informix.c
index 13058cf7bf..8fc0a467f7 100644
--- a/src/interfaces/ecpg/compatlib/informix.c
+++ b/src/interfaces/ecpg/compatlib/informix.c
@@ -811,7 +811,7 @@ rfmtlong(long lng_val, const char *fmt, char *outbuf)
 	/* and fill the temp-string wit '0's up to there. */
 	dotpos = getRightMostDot(fmt);
 
-	/* start to parse the formatstring */
+	/* start to parse the format-string */
 	temp[0] = '\0';
 	k = value.digits - 1;		/* position in the value_string */
 	for (i = fmt_len - 1, j = 0; i >= 0; i--, j++)