Synonyms: unfailing, unflagging
Definition: unceasing
Usage: unfailing loyalty; unfailing good spirits; unflagging courtesy
Similar words: constant
Definition: steadfast in purpose or devotion or affection
Usage: a man constant in adherence to his ideals; a constant lover; constant as the northern star
Synonyms: indefatigable, unwearying, unflagging, tireless
Definition: showing sustained enthusiastic action with unflagging vitality
Usage: an indefatigable advocate of equal rights; a tireless worker; unflagging pursuit of excellence
Similar words: energetic
Definition: possessing or exerting or displaying energy
Usage: an energetic fund raiser for the college; an energetic group of hikers; it caused an energetic chemical reaction