leastwise vs at any rate

leastwise and at any rate both are adverbs.

Word	Noun	Adjective	Verb	Adverb
leastwise	No	No	No	Yes
at any rate	No	No	No	Yes

As adverbs, leastwise and at any rate are synonyms defined as:

leastwise and at any rate: if nothing else (`leastwise' is informal and `leastways' is colloquial)

Other synonyms of leastwise include at least, leastways.

leastwise (adverb)	at any rate (adverb)
if nothing else (`leastwise' is informal and `leastways' is colloquial)	used to indicate that a statement explains or supports a previous statement
	if nothing else (`leastwise' is informal and `leastways' is colloquial)