مرتجلاً كان أو منقولاً أو غيرهما
Whether newly assigned, transferred to an established convention, or otherwise classified.
An expression that has acquired a recognized technical assignment differs from one used temporarily for a non-assigned meaning. A transferred term may be literally employed within its new register, even though its original lexical history is different.
This is why the convention-of-discourse qualification matters: conventional lexical transfer does not make every later use an original, fresh metaphor.