Merriam-Webster Collegiate Dictionary - slow

 I. adjective  Etymology: Middle English, from Old English slaw; akin to Old High German sleo dull  Date: before 12th century  1.  a. mentally dull ; stupid a ~ student  b. naturally inert or sluggish  2.  a. lacking in readiness, promptness, or willingness  b. not hasty or precipitate was ~ to anger  3.  a. moving, flowing, or proceeding without speed or at less than usual speed traffic was ~  b. exhibiting or marked by low speed he moved with ~ deliberation  c. not acute a ~ disease  d. low, gentle ~ fire  4. requiring a long time ; gradual a ~ recovery  5. having qualities that hinder rapid progress or action a ~ track  6.  a. registering behind or below what is correct the clock is ~  b. less than the time indicated by another method of reckoning  c. that is behind the time at a specified time or place  7.  a. lacking in life, animation, or gaiety ; boring the first chapter is a bit ~  b. marked by reduced activity business was ~ a ~ news week  • ~ish adjective  • ~ness noun  II. adverb  Date: 15th century ~ly Usage:  Some commentators claim that careful writers avoid the adverb ~, in spite of the fact that it has had over four centuries of usage have a continent forbearance till the speed of his rage goes ~er — Shakespeare. In actual practice, ~ and ~ly are not used in quite the same way. Slow is almost always used with verbs that denote movement or action, and it regularly follows the verb it modifies beans…are best cooked long and ~ — Louise Prothro. Slowly is used before the verb a sense of outrage, which ~ly changed to shame — Paul Horgan and with participial adjectives a ~ly dawning awareness…of the problem — American Labor. Slowly is used after verbs where ~ might also be used burn ~ or ~ly and after verbs where ~ would be unidiomatic the leadership turned ~ly toward bombing as a means of striking back — David Halberstam.  III. verb  Date: 1557  transitive verb to make ~ or ~er ; slacken the speed of ~ a car — often used with down or up  intransitive verb to go or become ~er production of new cars ~ed sharply  Synonyms: see delay