Possible Clues:

• Brusque, in sister's estimation
• Peter Sellers somewhat brusque?
• The leader from Ireland is anything but verbose
• In short, the trees have been chopped up
• Abrupt finish of Celt language
• 'Brief Encounter' secretly grips
• Not going on
• Brief accepted by barrister selectively
• Extract from chapter seen to be concise
• Like Coolidge's utterances