Costliest

Part of speech: adjective

Definitions

1. The greatest amount of money required for acquiring something
2. The maximum financial outlay necessary for a given item or service
3. Having the highest price among options or items

Etymology: "Costliest" is simply the superlative of "costly", the form used when comparing three or more things and picking the one that demands the most money. The superlative ending "-est" has been attached to adjectives in English since Old English, so the form itself is an ordinary piece of grammar rather than a special coinage. "Costly" comes from Middle English "costly", "costely" and "costeley", built from "cost" plus the suffix "-ly", which turns a noun into an adjective meaning "having the quality of" that noun. Its literal sense was therefore "having cost" or "full of cost", a plain description of expense. The sense of "expensive" grew naturally out of that root, so "costliest" carries the original idea of expense in its most extreme comparison.

Synonyms: most expensive, dearest, highest-priced, premium, lavish

Antonyms: cheapest, least expensive, inexpensive, affordable, bargain