Port and starboard are nautical terms with origins in Old English. Their meanings are simple: To an observer standing on a boat and facing the front of the craft, port is the left side of the boat, and starboard is the right. If it helps, remember it this way: both port and left are four-letter words.
Both adjectives are often used to make the phrasal adjectives port-side and starboard-side, which are hyphenated.
The following writers demonstrate correct use of port and starboard:
Once again, the quartermaster turns the wheel hard left to the port side of the ship. [BusinessWeek]
The others joined us. We were seated close by the starboard side of the destroyer . . . [Shoreline Times]
He is removing covers surrounding the port-side Solar Alpha Rotary Joint to begin applying fresh grease to the ring that allows the power-generating wings rotate and track the sun. [Spaceflight Now]
As our waiter Boyke brought breakfast to us, the beautiful cliffs of Sorrento, Italy, came into view on our starboard side. [The Province]
