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.

περίοδος ‘circuit’

Greek. – Grammar: n.

References: PH Heiberg: I.4:3, 76:10
Translated into:
Arabic: دورة [PH Morelon: I.4:3, 21:6]
Modern translations:
English: circuit [PH Hamm: I.4:3, 47:19]