Ansin is an adverb that means there, in that place.
It will be noted that the standard spelling of this word breaks the general rule in Irish of caol le caol, leathan le leathan (slender with slender, broad with broad), which states that velarised and palatalised consonants should not occur next to each other but that palatal-velar transitions should occur within vowel clusters.
Although this rule is by no means absolute, it should be remembered that it refers at least as much to phonemes as it does graphemes. When 'broken' in the standard written form, it still often prevails in naturalistic L1 speech: