seeming to have a reason; looking like there's more to it
Describes a person, expression, or situation that appears to have some hidden reason or special circumstances behind it. Often used when someone seems to be acting with an undisclosed motive.
His smile, which seemed to suggest there was more to it, bothered me.
She nodded as if she knew something more.
ありげ is a suffix meaning 'seeming to have' or 'appearing to be'; it attaches to nouns to form adjectival nouns indicating an appearance of possessing that quality.
Standard kanji spelling; 仔細 is the more common form in modern usage.
Alternate kanji spelling; 子細 is also used but less common than 仔細.
Compound of 仔細 (shisai, 'reason; circumstances') + ありげ (arige, 'seeming to have'). The suffix ありげ derives from classical あり (ari, 'to be') + げ (ge, 'appearance').