'iipach: "Man". This is the standard word for "man" in some non-'Iipay varieties, and considered slang in other dialects. The -ch here is part of the word, not a suffix. Similar to 'iipa, the most common word for "man" in Tiipay, also used by Robertson.
'eshin: "One, is one". Both a number and a verb. The speaker is fully enunciating here, and often shortens to shin, which is the more common variant in Tiipay.
"'Iipach 'eshin" would most commonly be found as a noun phrase in a larger sentence, meaning "a man" or "one man". Literally, it means "a man is one".