to make intense or more intense.

to make more acute; strengthen or sharpen.

Photography . to increase the density and contrast of (a negative) chemically.

to become intense or more intense.

verb

calm , lower , slow , soothe , weaken

verb

accent , accentuate , add fuel , add to , aggrandize , aggravate , augment , beef up * , boost , brighten , build up , concentrate , darken , deepen , emphasize , enhance , escalate , exacerbate , exalt , heat up , heighten , increase , intensate , lighten , magnify , point , pour it on , quicken , raise , redouble , reinforce , rise , rouse , set off , sharpen , spike * , step up , strengthen , stress , tone up , whet , bolster , elevate , mount