Entry 1 sense Webster, 1913

Hydrogenation

/hīdˌ-räjˌ-ən-āsh'-ən/ · Hy·dro·gen·a·tion · IPA /hˌaɪdrˌɑdʒənˈeɪʃən/

01 n. The act of combining with hydrogen, or the state of being so combined.

1.
The act of combining with hydrogen, or the state of being so combined.(Chem.)