ارتثأ

It (milk) thickened, or became thick: (S, K:) and so ↓ ارثأ, (M, K,) in some one or more of the dialects. (M.)

[Hence,] ارتثأ عَلَيْهِمْ أَمْرُهُمْ (assumed tropical:) Their case, or affair, became confused to them. (S, M.) And ارتثأ فِى رَأْيِهِ (assumed tropical:) He made a confusion in his judgment, or opinion. (S, K.) And هُمْ يَرْتَثِيءُونَ أَمْرَهُمْ (assumed tropical:) [apparently for فِى أَمْرِهِمْ, and thus meaning They are confused, or they make a confusion, in their case, or affair: or, otherwise, they confuse their case, or affair]: from الرَّثِيْيءَة; (T, TA;) and if so, tropical. (TA.)

-A2- Also He drank what is termed رَثِيْيءَة. (T, K.)