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.

محيط‘circumference’

Arabic

References: Alm. MS Tunis:
Translation of:
Greek: περιφέρεια [Alm. Heiberg: I.13, 70:19. – PH Heiberg: I.3:1, 74:7]
Synonyms:
الخطّ المحيط[PH Morelon: I.3:1, 19:5]
الخطّ المحيط[Plan. Sidoli+Berggren: 453, 455, 458]
الدائرة[Alm. MS Leiden: f. 6r]
خطوط محيطة بالدوائر[PH Morelon: I.19, 75:17]
دور[PH Morelon: I.18, 71:15]
محيط الدائرة[Alm. MS Tunis: ]