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.

ἔκκεντρος κύκλος ‘eccentric circle’

Greek

References: Alm. Heiberg: III.3, 217:8; III.3, 219:23,24,27
Translated into:
Arabic: الفلك الخارج المركز [Alm. MS Leiden: f. 38v; f. 39r]
Modern translations:
English: eccentric circle [Alm. Toomer: 141]
English: eccentre [Alm. Toomer: 145]