Semantics aims to describe the significance (or meaning) of linguistic expressions in a systematic way. Metasemantics, or foundational semantics, asks how expressions gain their significance in the first place - what makes it the case that expressions mean what they do. Metasemantics has recently been discussed extensively by philosophers of language, philosophers of mind, and philosophically minded linguists and psychologists. A large concern is semantic indeterminacy, the worry that there is no fact of the matter as to the semantic significance of our words. Ori Simchen offers a distinctly metasemantic strategy to counter this threat. 'Semantics, Metasemantics, Aboutness' is the first book-length treatment of metasemantics and its relation to the thriving research program of truth-conditional semantics.