motorsailer (plural motorsailers)
- (nautical) A vessel (usually a pleasure craft) that has been designed for both sailing and motor operation.
Practically all modern sailing vessels have a motor that can be used for propulsion. That alone does not make her a motorsailer. In a motorsailer some compromises (such as a shallower keel) have been made to make the vessel more suitable for motoring, and consequently less suitable for sailing than a typical sailing vessel.