张阿久
[zhāng ā jiŭ]
'张阿久' may just simply be someone's name, as '张' (zhāng) is one of the common Chinese surnames while '阿久' (ā jiǔ) is like an alias. The character '阿' preceding a name implies closeness or familiarity. If viewed in other angles or in specific situations, this might denote someone being casual yet approachable.