Omniverbum
From Tardis Wiki, the free Doctor Who reference
The Omniverbum is the term used for the longest word in existence, considered to be infinitely long, and possibly still being spoken. It was believed to have been the first word after Event One, coming out of the birthcries of the universe, when space was still small and sound could travel.
The Ish was an affix to the Omniverbum, and as it was sentient, it is possible the whole word was sentient. It is also possible that, as the Ish was found on Xenocubis, the Omniverbum either exists partly there or is worshipped there by the people who believe the universe and everything in it is echoes of Event One. (BFA: ...ish)