Is it proper to ‘mull things’?

‘Rollicking time,’ sang my husband to the tune of ‘Mull of Kintyre’. He had been amused to hear of this misapprehension of the lyrics and smugly enjoyed it not being his mistake for a change.

That kind of mull is a Gaelic word meaning ‘bare headland’. I think it is related to the Welsh word for a bare hill, moel, which Gerard Manley Hopkins used, with initial mutation, as voel in ‘The Wreck of the Deutschland’.

That is all very well, but I have been annoyed...