Meaning
"to make secure, safe, firm" (akin to asphales, "safe"), (a, negative, and sphallo, "to trip up"), is translated "make ... fast," in Act 16:24, of prisoners' feet in the stocks. In Mat 1:27-66, it is rendered "to make sure." See SURE.
Note: For HOLD (fast) and STAND (fast), see HOLD and STAND, No. 7.