From Longman Dictionary of Contemporary Englishpaintbrushpaint‧brush /ˈpeɪntbrʌʃ/ ●○○ noun [countable] 
DHAVPa brush for spreading paint on a surface
DHAVPa brush for spreading paint on a surfaceExamples from the Corpus
paintbrush• On colour monitors, the pointer can be used as a paintbrush.• Bwick uses his whole body for a paintbrush and has hair like Whoopi Goldberg.• If necessary, dust off the window and sill with a clean paintbrush.• His paintbrush does not lie - this countryside is idyllic.• Brush clean using an old paintbrush 4 Wearing rubber gloves, pour a little Ronseal Wood Hardener into the lid.• Apply enough pressure to force surplus putty out of the rebate 8 Lightly smooth with your fingers or with an old paintbrush.• Well, on opening the box, they certainly looked like artist's paintbrushes, finished in silver grey.• Unfortunately, I dropped the paintbrush, which of course went down the loo. 