
A level of support or resistance found on a head and shoulders pattern that is used by traders to determine strategic areas to place orders. Each peak of a regular head and shoulders pattern falls toward a support level, also known as a neckline, before it rises to create the next peak. A move below the neckline (in the case of a head and shoulders top) is used by traders as a signal of a reversal of the current uptrend. 
Investopedia Says:
It is possible to see the slope of a neckline be drawn at a slight angle rather than horizontal like the one shown in the image above. However, regardless of its slope, a move below the neckline of a regular head and shoulders pattern is always used as a signal of a move lower.
In the case of an inverse head and shoulders, the neckline is found as a level of resistance that has prevented the price from heading higher. A move beyond the neckline in this case would be used to signal the start of an uptrend.
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Dansk (Danish)
n. - halsudskæring
Nederlands (Dutch)
halsuitsnijding
Français (French)
n. - encolure, décolleté
Deutsch (German)
n. - Halsausschnitt
Ελληνική (Greek)
n. - ντεκολτέ, άνοιγμα λαιμού
Português (Portuguese)
n. - decote (m)
Русский (Russian)
вырез (платья)
Svenska (Swedish)
n. - ur/halsringning
中文(简体)(Chinese (Simplified))
领口, 领圈
中文(繁體)(Chinese (Traditional))
n. - 領口, 領圈
한국어 (Korean)
n. - 네크라인(드레스의 목을 판 선)
日本語 (Japanese)
n. - ネックライン, 襟足
العربيه (Arabic)
(الاسم) لباس, ( خاصه للنساء) طرفه الاعلى يصل إلى الرقبه او تحتها
עברית (Hebrew)
n. - קו הצוואר (בשמלה)