Entomology is the study of insects. Etymology is the study of words.

Ordinance – a rule or decree Ordnance – weaponry or ammunition

A capella.

Fowl is a bird. Foul means loathsome or offensive.

Gaff is a hook. Gaffe is an embarrassing mistake.

Gild means to cover in gold. A guild is a professional organization.

Mock – to make fun of, or to copy, something. Mach – a number that indicates the ration of speed of an object in comparison to the speed of sound.

Whet – you whet your appetite Wet – to saturate something with a liquid

Exceed – to go beyond Accede – to give in

Already is an adverb that means something that occurred in the past. All ready is a statement of completeness.