Neck - Vine's Expository Dictionary of New Testament Words
Neck[ 1,,G5137, trachelos ]
(a) literally, Matthew 18:6; Mark 9:42; Luke 17:2; of embracing," Luke 15:20; Acts 20:37;
(b) metaphorically, in Acts 15:10, of "putting a yoke upon;" Romans 16:4, singular in the original, "(laid down their) neck," indicating the figurative use of the term rather than the literal. Prisca and Aquila in some way had risked their lives for the Apostle (the phrase is found with this significance in the papyri).