Gave up and looked up answers . Never heard of 12a -tricky when you have have cepbl to fit in and they make equally possible names.
14a Thought it must be bias with bias sounding like some word I'd never heard of. I don't get how first born can be anything but singular.
Tx Chrise an PDS. I had considered that. But could not rationalise the synonyms. However, my Concise Oxford Thesaurus has them. COT hasn't been off shelf for a very long while. Apps not foolproof,however, convenient.