consideration has 5 distinct synonyms spread across 4 of its 6 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 inconsideration.
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.
the process of giving careful thought to something
information that should be kept in mind when making a decision
“another consideration is the time it would take”
a discussion of a topic (as in a meeting)
“consideration of the traffic problem took more than an hour”
kind and considerate regard for others
“he showed no consideration for her feelings”
a fee charged in advance to retain the services of someone
Synonyms, antonyms and the broader and narrower relations for consideration come from Princeton University’s WordNet. Full sources and licences.