This article deals with the identification and interpretation of two rare Middle Persian words. Firstly, some attestations of the as yet unrecognized word <hs’lyh> hassārīh are discussed, showing that it means “direction”. Then, a semantic analysis of its underived counterpart hassār is carried out, as a basis for an etymological proposal. Finally, it is argued that hassār descends from Old Persian *haçā-sāra- “(having the head) in the same direction”, and a possible reconstruction of the semantic development of the word is provided.