Disyllabic nouns with the meaning of “measurable quantity” are part of a broader group of feminine nouns with the alternative endings nom. sing. -ě/0 and acc. sing. -u/0 that contributed to the formation of the new declension paradigm píseň in Old Czech. Despite temporary uniform shift towards this declension paradigm in Middle Czech, the nouns with the meaning of “measurable quantity” or “measurable dimension” don’t evolve in the same way in the following Modern Czech: their evolution is determined by the quality of the root vowel.
The feminine nouns with the root -ou- and -á- (hloub, tloušť, dál) shift to i-stems, the noun dél keeps on declining according to the paradigm píseň. Lexemes with a high front root [i:]restore both the original long disyllabic form nom./acc. sing. (blíž/blíže, níže, šíře/šíř, tíže/tíž, výše/výš) and also its original declension.
Archaisms and poetic expressions blíž, dél, tloušť disappear during the Modern-Czech period. Throughout their existence, the nouns occur frequently as a part of adverbial compounds (cf.
Old-Czech vzšířu, vzvýšu, Middle-Czech podél, zdélí, etc.) and some of them become new independent lexemes over time.