words whose meanings are nothing like they sound like they would mean: fecund

Fecund.

It sounds...gross. Like it would be something vaguely decrepit, decaying. I was going to use it in relation to the end of a Zola novel. Then I realized that I was pretty sure it didn't mean what I thought it meant. You know, grossness. Maybe it's because it sounds like fecal? It almost rhymes with wanton and worsen (also gerund!).

It really means, according to the good ol' OED:

1. a. Of animals, the earth, etc.: Capable of producing offspring or vegetable growth abundantly; prolific, fertile.
2. Producing fertility, fertilizing. Cf. FECUNDITY

Who would have thought?