WordNet records no synonym and no antonym for divot. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(golf) the cavity left when a piece of turf is cut from the ground by the club head in making a stroke
“it was a good drive but the ball ended up in a divot”
a piece of turf dug out of a lawn or fairway (by an animals hooves or a golf club)
Synonyms, antonyms and the broader and narrower relations for divot come from Princeton University’s WordNet. Full sources and licences.