Answer: oxidize

AnswerCrossword Clue
OXIDIZEBecome rusty
OXIDIZEBecome rusted
OXIDIZEDiscolor, as banana peels, e.g.
OXIDIZEBecome ash, maybe
OXIDIZEGet rusty
OXIDIZEBegin to rust
OXIDIZERust
OXIDIZEForm rust, say
OXIDIZEGo from aluminum to alumina, say
OXIDIZERust out
OXIDIZEGet rusty e.g.
oxidizeto become oxidized
oxidizeto combine with oxygen, also OXIDISE
oxidizeto combine chemically with oxygen