1630s, "type of plasterer's fine paste or cement," from French potée "polishing powder" (12c.), originally "pot-full, contents of a pot," from Old French pot "container" (see pot (n.1)).
From 1660s as "powder used for polishing glass or metals." The meaning "soft pasty mixture for sealing window panes" is recorded by 1706. Figurative use in reference to one easily influenced is from 1924. Putty knife, one with a blunt, flexible blade, used by glaziers, etc., for laying on putty, is attested from 1834.
"to cover with putty, mend or join with putty," 1734, from putty (n.). Related: Puttied; puttying.