To rebutton is to button again, typically after buttons have come undone or were unfastened: She rebuttoned her coat against the wind.
The word often appears in contexts of adjusting clothing that's become disheveled or was opened temporarily.
1. garment — fastens, Attaches or secures; secures (Makes fast or safe); closes (Brings to an end); refastens (Secures something again); attaches · shirt · coat · jacket · cardigan · blouse · cuff · placket · closure · mend
2. digital — interface, Shared connection point; click (Brief sharp noise); toggle (Two-position switch); reset (Restore to original state); reactivate · UI · menu · toolbar · restore · settings · widget · checkbox · radio · form