slow / slō/ • adj. 1. moving or operating, or designed to do so, only at a low speed; not quick or fast: a time when diesel cars were slow and noisy | a slow dot-matrix printer. ∎  taking a long time to perform a specified action: she was a slow reader | large organizations can be slow to change. ∎  lasting or taking a long time: a slow process | the journey home was slow. ∎  not allowing or intended for fast travel: the slow lane. ∎  (of a playing field) likely to make the ball bounce or run slowly or to prevent competitors from traveling fast.2. (of a clock or watch) showing a time earlier than the correct time: the clock was five minutes slow.3. not prompt to understand, think, or learn: he's so slow, so unimaginative.4. uneventful and rather dull: a slow and mostly aimless narrative. ∎  (of business) with little activity; slack: sales were slow.5. Photog. (of a film) needing long exposure. ∎  (of a lens) having a small aperture.6. (of a fire or oven) burning or giving off heat gently: bake the dish in a preheated slow oven.• adv. at a slow pace; slowly: the train went slower and slower | [in comb.] a slow-moving river. • v. [intr.] reduce one's speed or the speed of a vehicle or process: the train slowed to a halt investment has slowed down | [tr.] he slowed the car. ∎  (slow down/up) live or work less actively or intensely: I wasn't feeling well and had to slow down.PHRASES: slow but sure not quick but achieving the required result eventually: a slow but sure increase in the price of gold.DERIVATIVES: slow·ish adj.slow·ness n.