It belongs to a phonetic family with 泳 and 詠 — they share the 永 component and the reading エイ.
A common word using 永 is 永遠 (えいえん), meaning “eternity, perpetuity, immortality”.
Don't confuse it with 泳, 詠, 氷, and 水 — 氷 (ice) is 水 with a dot; 永 (eternal) has a dot and a top stroke
