Relating to or requiring careful, thorough thinking; capable of or characterized by working something out through thought.
From 'excogitate' + '-ive' (tending to, capable of). The '-ive' suffix creates an adjective describing a quality or capability.
This adjective is rarely used now, but when it appears in old texts, it describes intense mental activity—'excogitative effort' suggests thinking is real work requiring genuine talent and focus.
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