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.

rigid, lit. incapable of turning (LSJ) ‘incapable of turning’

English

References: Alm. Toomer: 63
Translation of:
Greek: ἀδιάστροφος [Alm. Heiberg: I.12, 66:7]