Tawassut, also called bayniyyah, is the intermediate quality: sound is neither completely arrested as in shiddah nor freely flowing as in rikhawah. It occupies a distinct middle position.
Its five letters are gathered in لِنْ عُمَرْ: ل، ن، ع، م، ر. Compare the unvowelled consonants in «أَلْ», «أَنْ», and «أَمْ» with sounds such as ق and س.
Comparison: ق illustrates shiddah, س illustrates rikhawah, and ل illustrates tawassut. Tawassut is not a mixture of two mutually opposed labels on one letter; it is its own intermediate phonetic condition.