Hefty means large, heavy and substantial. A hefty book, a hefty fine, hefty and solid.
It works for physical weight and for amounts alike — a hefty sum, a hefty increase, a hefty bill — and it is one of the most useful informal words for a number that is bigger than expected. Of a person it means solidly built. Note heft as a noun meaning weight, and as a verb meaning to lift something to judge its weight, which is the sense the adjective comes from.
1adjectiveheftyLarge, heavy and substantial.
“He carried a hefty suitcase up three flights of stairs.”
synonyms: substantial, weighty
hefty is a quality of weight.
Heft plus -y, from the nineteenth century, and heft is an English formation from heave. The resemblance to German heftig, meaning violent, is apparently coincidental.
Middle English
heft — heaviness; something heavy, a weight
English
heft
English, today
hefty
Built from
19th century. From heft + -y. The similarity with German heftig (“vigorous, violent, intense”) is apparently coincidental. From the German are Dutch -, Danish -, Norwegian heftig, Swedish häftig. heft The noun is derived from Late Middle English heft (“heaviness; something heavy, a weight”), from heven (“to lift, raise”) + -th, by analogy with the development of weft from weven (modern English weave), etc. (also compare words like cleft from cleave, and theft from thieve, where the development occurred in Old English or earlier languages). The English word is analysable as heave + t. The verb is probably derived from the noun.
Etymology from Wiktionary, CC BY-SA