From Longman Dictionary of Contemporary Englishcotton budˈcotton bud noun [countable] British English 
DCBa small thin stick with cotton wool at each end, used for cleaning places that are hard to reach, such as inside your ears SYN Q-tip American English
DCBa small thin stick with cotton wool at each end, used for cleaning places that are hard to reach, such as inside your ears SYN Q-tip American EnglishExamples from the Corpus
cotton bud• She licks the tip of a cotton bud and begins to comb her eyebrows.• Use a cotton bud to blend the colours together, so there are no hard lines.• Use a cotton bud to carefully blend away edges into foundation so there is no hard edge.• Then smudge downwards towards the lashes, using a cotton bud or a small brush.• Remove any blobs with a damp cotton bud. 