Probably from sbirciare (“to peep”). Hyphenation: bìr‧cio <span class="searchmatch">bircio</span> (feminine bircia, masculine plural birci, feminine plural birce) (obsolete, regional)...
See also: Boriçi borici m pl masculine plural of borico <span class="searchmatch">bircio</span>, cibori...
peek at Conjugation of sbirciàre (-are) (See Appendix:Italian verbs) <span class="searchmatch">bircio</span> sbirciata sbirro ^ sbirciare in Treccani.it – Vocabolario Treccani on line...