Pronunciation (UK) IPA (key): /ˈsplɪntə(r)/ (US) IPA (key): /ˈsplɪntɚ/ or [ˈsplɪɾ̃ɚ] Audio (US)(file) Audio (AU)(file) Noun Singular splinter Plural splinters (countable) A splinter is a long, small, sharp piece of something, usually wood. This short entry needs someone to make it better. You can help Wiktionary by adding to it.Wikiwand - on Seamless Wikipedia browsing. On steroids.