tsa’aq, “to cry out,” strong’s H6817

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.

THE ANCIENT HEBREW LEXICON | INDEX OF HEBREW ROOTS