Webster's 1913 Dictionary
LOGGERHEADS
LOGGERHEADS Log "ger *heads `, n. (Bot. )
Defn: The knapweed.
American Oxford Thesaurus
loggerheads
loggerheads plural noun PHRASES at loggerheads the European Union and the United States are at loggerheads over how to reduce greenhouse gases: in disagreement, at odds, at variance, wrangling, quarreling, disagreeing, disputing, locking horns, at daggers drawn, in conflict, fighting, at war; informal at each other's throats.
Oxford Thesaurus
loggerheads
loggerheads plural noun PHRASES at loggerheads local councillors have found themselves at loggerheads with the Government: in disagreement, at odds, at variance, in opposition, at cross purposes, out of step, quarrelling, clashing, at outs; in conflict, at war, at daggers drawn, fighting, wrangling, feuding, conflicting, locking horns, estranged; informal at each other's throats, like cat and dog.