Usufructuary = one who benefits from another’s labor

Deleterious = having a nullifying effect

Perspicacity = perceptiveness

Peristalsis = the muscular action of the esophagus

Colloquialism = old saying or way of phrasing in speech

Soliloquy = a speech or a single voice speaking

Hysteresis = mechanical loss of velocity

Anthropomorphize = To make human or to attribute human qualities in a non-human thing or animal

Bonus words

Pachyrhinocephalosaurus = thick-skulled dinosaur

Salpingo-oopherectomy = removal of the female reproductive organs

Note: some of these will not appear in an ordinary dictionary as they are either technical terms unique to a science or very obscure.