Eccentrics beginning to cause rows (6)
I believe the answer is:
cranks
'eccentrics' is the definition.
(crank is a kind of eccentric)
'beginning to cause rows' is the wordplay.
'beginning to' indicates taking the first letters.
'rows' becomes 'ranks' (I've seen this before).
The first letter of 'cause' is 'c'.
'c'+'ranks'='CRANKS'
(Other definitions for cranks that I've seen before include "Drugs" , "people irascible in America" , "People with crazy ideas" .)