Y crossn.(a) a cross in the form of the letter Y, often used as an ornamental device on ecclesiastical vestments;(b) a piece of piping consisting of three branches diverging at acute angles.
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Y cross1881
1881 G. G. ScottEss. Hist. Eng. Church Archit. 114 St. Regnobert's chasuble at Bayeux, and St. Thomas's at Sens, are examples of the use of the Y cross in France.
a1884 E. H. KnightPract. Dict. Mech. Suppl. 959/1Y Cross, a pipe with two divergent stems.