Collocations for rigid - adj.

appear, be, seem
become, grow
He grew even more rigid and uncompromising as he got older.

extremely, fairly, very, etc.
We operate within fairly rigid parameters.

entirely
An entirely rigid system is impractical.

increasingly
excessively, overly
relatively

be, feel, lie, look, sit, stand
She feigned sleep, lying rigid in bed.

become, go, turn
remain

very
absolutely, completely, quite
almost

with
He went absolutely rigid with shock.

Rigid is used with these nouns:
adherence, attitude, confines, conformity, convention, definition, discipline, distinction, division, dogma, hierarchy, orthodoxy, packaging, plastic, rule, schedule, separation, stance, structure, system