<pre>
Q: What are some examples of idioms that include obsolete words?

A: These are called fossil expresions -- words that have dropped out of
common use but hang around in idioms.  Not all of them are separate
words, some are part of other words or have prefixes or suffixes
attached.  There are also words which have current meaning, but the
meaning in the idiom is unrelated to it.

 idiom           	fossil          meaning of fossil
 --------------------------------------------------------
 swashbuckler		buckler		small shield
 newfangled		fangled		siezed
 rank and file		file		column
 to and fro		fro		from
 gormless		gorm		attention
 hem and haw		haw		make the sound "haw"
 hem and haw		hem		make the sound "hem"
 hue and cry		hue		outcry
 kit and kaboodle	kaboodle	collection
 out of kilter		kilter		order
 kith and kin		kith		friends
 let or hindrance	let		hindrance
 footpad		pad		highwayman
 pratfall		prat		buttocks
 rank and file		rank		row
 raring to go		raring		enthusiastic
 ruthless		ruth		compassion
 short shrift		shrift		confession
 spick-and-span		span		chunk of wood
 spick-and-span		spick		nail (spike)
 swashbuckler		swash		bluster or stagger
 bank teller		tell		to count
</pre>
