"An art of the boring, by lexical necessity, cannot pre-date romantacism.... Earlier one may have fidgeted, felt listless or succumbed to accidie.... Comparable to the graduate vitiation of affect in the meaning of the words dreadful," "awful," "terrible," etc., "boredom" marks the historical boredom with abhorrence (orthographically the Spanish aburrir still maintains closer ties with the Latin "abhorrere," although it has undergone the same semantic shift)." ~ J. Phillips, "Beckett's Boredom" in Essays on Boredom and Modernity (2009)

Notice that acá's story is one of consistent reinforcement as the word loses semantic strength over time. Originally, Indo-Europeans added *h₁e- and *-ḱe to mean "this here." By the time of the Proto-Italic period, the word (now *ek(e)) had weakened in meaning and the Italic people felt the need to reinforce it with the suffix *-ke "here" much as their ancestors had done several thousand years before them. As time went one, the Italic word evolved into Latin ecce and (again) weakened in meaning. The Latin speakers felt the need to reinforce the word with hac, and that eventually became Spanish acá.

Mas acá, meaning "this side" or "this way," derives from its use as an intensifier. Unlike mas allá, which neatly translates as "beyond," mas acá has no isomorphic equivalent.