PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

διάμετρος‘diameter’

Greek. – Grammar: n.

References: Alm. Heiberg: I.10, 31:14, 32:10-11. – PH Heiberg: I.10:3, 86:2
Translated into:
Arabic: قطر الدائرة/ قطر [Alm. MS Leiden: f. 6r]
Arabic: قطر [PH Morelon: I.10:3, 33:7]
Arabic: قطر [Alm. MS Tunis: ]
Modern translations:
English: diameter [PH Hamm: I.10:3, 53:9]
English: diameter [Alm. Toomer: 48]