しかし

Etymology 1
→ →

Originally +. This abbreviated from shikari shi to shikasshi, and then shortened further to shikashi.

The initial sense may have been parseable as that [preceding statement] being so, ..., much like English phrases such as be that as it may or that said, followed by a statement in opposition to the earlier statement.

Conjunction

 * 1)  but, however
 * 2) * 1911, 与謝野晶子, 産屋物語: