Synonyms of lifelong

1 Syllable
old
2 Syllables
yearlong, long-term, constant, chronic, lasting, longterm
3 Syllables
enduring, perennial, persistent, continuing, livelong, deep-rooted, lingering, longstanding, hardcore, long-lived, long-lasting, long-standing, permanent
4 Syllables
lifetime, habituated, ever-present, unabating
5 Syllables
inveterate