Another example of where context is required: port
In general it means a "connection" point, but in a firewall rule dst-port is part of a protocol, not connection point for a wire.
Also consider this
/interface bridge port
add bridge=bridge comment=defconf interface=ether2
What this is doing is adding the physical ethernet port ether2 to the bridge devices' "switch" ports. After this, ether2 should not be used directly by the router, i.e. you shouldn't apply an ip address to ether1, although ROS won't prevent it, at least is didn't in the past. The command is changing the meaning of the name ether2 from a "router interface" to a "bridge-port of the bridge device. After this, from the "router block"'s point of view, ether2 should be ignored. The ether2 port now belongs to a switch connected "through" the bridge interface, and a device on ether2 is then accessed by the router through the bridge "interface". This isn't obvious from the terminology used. This won't change, so you just have to understand the context provided by /interface bridge port, and you have to know that a bridge is a "trinity" of things, a connection point for the router to connect to the switch ( the switch-facing interface of the router), a connection point from the switch to the router ( the router-facing port of the virtual switch), and the virtual switch which has all the capabilities of a switch (mac address table with the ability to learn, flood and forward, i.e. all the things a switch can do)
Last paragraph edited to hopefully make it clearer, but writing isn't my stong point.