Meanings of mere synonym in английском

Is that great title a mere synonym for the half-heathenish idea of the 'God of battles'?

And the mind equally rejects the repetition of the word and the use of a mere synonym for it,-e.g.

Under the head of definition must be included all propositions in which the predicate is a mere synonym of the subject, e.g.

Now that expression is no mere synonym for kindness exceeding great, but it unfolds what was at once David's deepest motive and his bright ideal.

'Categorical' properly means 'predicable' and 'hypothetical' is a mere synonym for 'conditional.'

'Full of years' does not seem to me to be a mere synonym for longevity.