slacken

v. （使）松弛，放松

skulk, skull, skull and cross-bones, skull-cap, skunk, sky, sky-blue, sky-diver, sky-diving, sky-high, sky-rocket, sky-writing, skylark, skylight, skyline, skyrocket, skyscraper, skywards, slab, slack, slacker, slackly, slackness, slag, slag-heap, slain, slake, slalom, slam, slander, slanderer, slanderous, slanderously, slang, slanginess, slangy, slant, slanted, slantingly, slantwise, slap,