slot has 3 distinct synonyms spread across 3 of its 8 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
a position in a grammatical linguistic construction in which a variety of alternative units are interchangeable
“he developed a version of slot grammar”
a small slit (as for inserting a coin or depositing mail)
“he put a quarter in the slot”
Synonyms, antonyms and the broader and narrower relations for slot come from Princeton University’s WordNet. Full sources and licences.
a time assigned on a schedule or agenda
“the TV program has a new time slot”
a position in a hierarchy or organization
“Bob Dylan occupied the top slot for several weeks”
the trail of an animal (especially a deer)
“he followed the deer's slot over the soft turf to the edge of the trees”
(computer) a socket in a microcomputer that will accept a plug-in circuit board
“the PC had three slots for additional memory”
a slot machine that is used for gambling
“they spend hours and hours just playing the slots”
assign a time slot
“slot a television program”