second has 20 distinct synonyms spread across 11 of its 15 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. Its one recorded opposite is first.
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.
1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites
the fielding position of the player on a baseball team who is stationed near the second of the bases in the infield
a 60th part of a minute of arc
“the treasure is 2 minutes and 45 seconds south of here”
the official attendant of a contestant in a duel or boxing match
a speech seconding a motion
“do I hear a second?”
the gear that has the second lowest forward gear ratio in the gear box of a motor vehicle
“he had to shift down into second to make the hill”
merchandise that has imperfections; usually sold at a reduced price without the brand name
transfer an employee to a different, temporary assignment
“The officer was seconded for duty overseas”
a part or voice or instrument or orchestra section lower in pitch than or subordinate to the first
“second flute”
Synonyms, antonyms and the broader and narrower relations for second come from Princeton University’s WordNet. Full sources and licences.