英倫三島

Proper noun

 * 1)  United Kingdom; British Isles; Crown Dependencies; Great Britain, etc. inaccurate and non-specific geographical designation

Usage notes
The phrase likely originated from unclear or erroneous concepts by some 19th-century writers. It is commonly interpreted as Isle of Man also included besides the two main islands, yet unconvincing. It is still in current usage as a set phrase, but is avoided where it is desirable to maintain geographic clarity and accuracy.