The first occurrence.
And He said: What have you done? The voice of your brother’s blood cries out to Me from the ground. Gen 4:10
The primitive root.
Strong’s H6817 צעק tsa’aq , a primitive root meaning, “to loudly call.” The 3-letter root is tsadey + ayin + quph. However, the Ancient Hebrew Lexicon indicates the original pictograph was a chet, perhaps replaced by a quph over time because of their similar sounds. Thus:
tsadey צ, ץ = the trail, thus a man concealed, journey, chase, hunt
ayin ע = the eye, thus watch, know, shade
chet ח = the wall, thus outside, divide, half
The story: Searching (tsadey) diligently with the eye (ayin) outside (chet), for something lost, or needed, is implied by loud calling.