Fetching details from the dictionary...
boorish; unrefined; rustic; uncouth; clumsy; brusque
彼は昔ながらの無骨な男だった。
He was a rustic man of the old school.
その老職人は無骨に鉄を打ち続けた。
The old craftsman continued to boorishly hammer the iron.
彼の話し方は無骨だが、その言葉から誠実さが強く伝わってきた。
His way of speaking was brusque, but a strong sincerity came through from his words.