also: あん
pre-noun adjectival
Pre-noun adjectival (rentaishi) referring to something distant from both speaker and listener, or a situation unfamiliar to both. Used before a noun to indicate 'that ... over there' or 'that ... we both know about'.
あの本を取ってください。
Please pass me that book over there.
あの時は本当に楽しかったね。
That time was really fun, wasn't it?
That person over there is my teacher.
That was really tough, wasn't it, back then?