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.

مسطوح‘plane’

Arabic

References: Alm. MS Tunis:
Translation of:
Greek: ἐπίπεδος [Alm. Heiberg: I.3, 13:15; I.4, 15:18]
Synonyms:
بسيط[PH Morelon: I.12:1, 43:3]
بسيط [Alm. MS Tunis: ]
سطح[PH Morelon: I.9:1, 29:2; I.11:1, 37:17]