Terve vs Derve - What's the difference?

As verbs the difference between terve and derve

is that terve is (label) to fall; be thrown down while derve is to labour; swink.

(en-verb)

(label) To fall; be thrown down.

(label) To dash down; cast; throw: in combination with (m); to overthrow; overturn.

(label) To turn down or back; roll or fold over.

(derv)

To labour; swink.

To trouble; grieve; hurt; afflict; molest.