The reason of borrowings:
1. to fill a gap in vocabulary
«Potato»,»tomato» from Spanish when appeared in English (these vegetables)
2. It represents the same concept but in some aspect: a new shade of meaning. Ex.: friendly-cordial (Latin), Desire(French)-wish, Admire(Latin)-adore( French)
When borrowed words become assimilated in the language and the process of assimilation develops to the point when it’s practically impossible to recognize the origin of a word. Ex.: cat, dinner,...
Other words bear trace of their background.
Ex.: distance, development (French suffixes); Skin, sky (Scandinavian); Police, garage, cafe (French) Stress on the last syllable.
Some Norman borrowings have become fully adopted, no phonetic traces of their French origin: table.
«Big in size» as first it retained a trace of it’s former meaning «wide» because it was applied to object with vast horizontal dimension.
Nowadays it has approached very closely to the word «big».
Etymological survey of Modern English