The point of the entry is to distinguish two words, qurai=os and qureo/s, that would have been homophonous in late Greek apart from accent. The latter refers to a shield that is large and door-shaped (i.e. oblong), like the Roman scutum; see under epsilon 3802, theta 605 and, for example, Polybius 2.30.3 (web address 1). Hesychius theta927 presents much the same distinction in reverse order.
[1] Adler cites the Ambrosian Lexicon (392) as a comparandum.
[2] cf. [Herodian], Partitiones 61.