increase - become bigger or greater in amount; "The amount of work increased"

screw up, hot up, heat up - make more intense; "Emotions were screwed up"

fan - make (an emotion) fiercer; "fan hatred"

enhance, heighten, raise - increase; "This will enhance your enjoyment"; "heighten the tension"

amplify - increase the volume of; "amplify sound"

sharpen - make sharp or sharper; "We had to sharpen our arguments"

heighten, sharpen - make (one's senses) more acute; "This drug will sharpen your vision"

increase - become bigger or greater in amount; "The amount of work increased"

build - develop and grow; "Suspense was building right from the beginning of the opera"

redouble - make twice as great or intense; "The screaming redoubled"

erupt, flare up, irrupt, break open, burst out, flare - erupt or intensify suddenly; "Unrest erupted in the country"; "Tempers flared at the meeting"; "The crowd irrupted into a burst of patriotism"

condense - become more compact or concentrated; "Her feelings condensed"

sharpen - become sharp or sharper; "The debate sharpened"

accelerate, quicken, speed up, speed - move faster; "The car accelerated"

enlarge - make larger; "She enlarged the flower beds"

change - undergo a change; become different in essence; losing one's or its original nature; "She changed completely as she grew older"; "The weather changed last night"