Synonyms For "Intelligent" :
1 syllable:
apt, born, bright, quick, smart, sound
2 syllables:
agile, brainy, brilliant, clever, healthy, innate, nimble, ready, searching, thinking, trenchant
3 syllables:
natural, precocious, prehensile, rational, reasoning, sensible
4 syllables:
levelheaded, reasonable, scintillating