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pielga f. (Noun) (Salamanca) "wooden cattle hitch measuring 30 cm"
From a pre-form *pelga, from Latin pedica "fetters," "snare." The d developed into -l- due to palatization and syncopation in Vulgar Latin. Latin pedica is from a surviving weak stem ped- "foot" in Latin, from Proto-Italic *ped- 'id.' For a continued etymology, see pie.

Regarding the Latin stem ped- and the nominative singular pes "foot:" the stem is from the Proto-Italic genitive *ped-s via Lachmann's Law, where *-d was lost while *-e- underwent compensatory lengthening, and replaced the Proto-Italic nominative singular *pōd-.