impetus, impulsion, urge, caprice, vagary, pulsing, whim, pulsation, momentum, nerve impulse, more...

deliberation, caution, planning, restraint, thoughtfulness

sudden, compulsive, irresistible, spontaneous, uncontrollable, automatic, instinctive, reflexive, more...

first, sudden, natural, creative, strongest, irresistible, sexual, specific, initial, religious, original

sudden feeling,   quick decision,   sudden urge,   sudden action,   snap decision,   impulsive passion,   urge to,   urge to action,   sudden desire,   sudden decision