lather/ 'lɒːðər /

1.noun [s/u] 
(soapy) 泡沫

2.vt.[+hair] [ fabric] 
涂泡沫于

3.vi.[soap etc+] 
起泡沫

to get in a lather {or} to work o.s. up into a lather (over {or} about sth)
(对某事)过分焦躁不安