Leek and Spring onion

Leek noun - Plant having a large slender white bulb and flat overlapping dark green leaves; used in cooking; believed derived from the wild Allium ampeloprasum.

Spring onion and leek are semantically related in green onion topic. In some cases you can use "Spring onion" instead a noun "Leek".

Spring onion noun - A young onion before the bulb has enlarged; eaten in salads.

Leek and spring onion are semantically related in green onion topic. You can use "Leek" instead a noun phrase "Spring onion".