unmensurable
/(ˌ)ʌnˈmɛnʃ(ʊ)rəbl/ /(ˌ)ʌnˈmɛnsjʊrəbl/ /(ˌ)ʌnˈmɛns(ə)rəbl/Originally Scottish. Now somewhat rare
adjective
Not measurable, immeasurable.
Origin
Early 16th century; earliest use found in Gavin Douglas (c1476–1522), poet and bishop of Dunkeld. Apparently from un- + mensurable.