Come up with (an idea, plan, explanation, theory, or principle) after a mental effort:
— Excogitate a way to measure the speed of light.

synonyms: contrive, devise, forge, formulate, invent.

Roget 515: imagine, fancy, conceive; idealize, realize; dream, dream of, dream up; give to airy nothing a local habitation and a give to airy nothing a local habitation and a name" [Midsummer Night's Dream]. create, originate, devise, invent, coin, fabricate; improvise, strike out something new.    set one's wits to work; strain one's invention, crack one's invention; rack one's brains, ransack one's brains, cudgel one's brains; excogitate^†; brainstorm.    give play, give the reins, give a loose to the imagination, give fancy; indulge in reverie.    visualize, envision, conjure up a vision; fancy oneself, represent oneself, picture, picture-oneself, figure to oneself; vorstellen [G.].    float in the mind; suggest itself etc. (thought) 451.    ... show more

Dutch: uitdenken

Reflect deeply on a subject:
— The scientist must stop to observe and start to excogitate.

synonyms: chew over, contemplate, meditate, mull, mull over, muse, ponder, reflect, ruminate, speculate, think over ... show more.

Roget 451: think, reflect, cogitate, excogitate^†, consider, deliberate; bestow thought upon, bestow consideration upon; speculate, contemplate, meditate, ponder, muse, dream, ruminate; brood over, con over; animadvert, study; bend the mind, apply the mind etc. (attend) 457; digest, discuss, hammer at, weigh, perpend; realize, appreciate; fancy etc. (imagine) 515; trow^†.    take into consideration; take counsel etc. (be advised) 695; commune with oneself, bethink oneself; collect one's thoughts; revolve in the mind, turn over in the mind, run over in the mind; chew the cud upon, sleep upon; take counsel of one's pillow, advise with one's pillow.    rack one's brains, ransack one's brains, crack one's brains, beat one's brains, cudgel one's brains; set one's brain to work, set one's wits to work.    harbor an idea, entertain an idea, cherish an idea, nurture an idea etc. 453; take into one's head; bear in mind; reconsider.    occur; present itself, suggest itself; come into one's head, get into one's head; strike one, flit across the view, come uppermost, run in one s head; enter the mind, pass in the mind, cross the mind, flash on the mind, flash across the mind, float in the mind, fasten itself on the mind, be uppermost in the mind, occupy the mind; have in one's mind.    make an impression; sink into the mind, penetrate into the mind; engross the thoughts.    ... show more

Dutch: overpeinzen, overdenken, overwegen, stilstaan bij, contempleren, mediteren, studeren