'Ownership is defined as the right to exclude others'
I'm reminded of the English legal theorist, Blackstone's definition : ownership is 'that sole and despotic dominion which one man (sic) exercises over the external things of the world, in total exclusion of any other individual in the universe' (2 William Blackstone, Commentaries *2.)
Ownership as control of use
I prefer a different approach. Sole control over an asset, with the right to exclude all others from its use, does not seem to me the most fruitful or most realistic route to understanding the nature of property. Ownership seems to me esssentially tied to the control of some aspect of a particular thing's use. More specifically :
a property right should be understood as a right conferring some measure of
legal authority to determine how a particular thing may be used — authority that
comes at the expense of all others asserting authority over the use of the thing. (James Y. Stern, 'Property's Constitution', California Law Review, Vol. 101, No. 2 (April 2013), pp. 277-326: 283.)
the law of property tells us who is in charge and to what
extent as well as who has authority to decide how the thing will be used when
disputes over use arise. The basic structure of property law is something like
what parents do when they sew nametags into their children's clothes before
sending them to summer camp. Property law affixes a sort of invisible tag to
every object in the world, naming the person authorized to decide how to use
the object. There need not be a single name on the tag—B might be empowered
to make most decisions subject to an exception allowing A to decide some
particular question or to take over at some particular point in time. The
permutations can be exceedingly complex. But it is important to recognize the
sort of conflicts that the law of property addresses—conflicts arising from
competing claims to control some particular resource—and the way it addresses
them. Property law tells us who gets to decide how a given resource may be
used. (Stern: 294.)
Limits to control of use
This passage presents a more complex and to my mind more realistic account of the general nature of property rights and hence of ownership. Something may be my property, therefore something I own, but the extent to which I can determine how a particular thing (my property) can be used may be limited. What's more, I am unlikely in any system of property rights to have the sole, and in some cases any, authority in a dispute over how my property will be used. I may own a strip of land but it may include a public right of way; and I will be unlikely to have the authority, legal and I should add moral, to use my land as I wish if I obstruct the needful public take-over of the land in a humanitarian catastrophe.
I'd add that ownership may not be all or nothing. I may have the sole right to determine most but not all uses of a thing. I have the sole right to determine the use of a litre of sulphuric acid in cleaning my drains but no right to serve it to a guest as a drink.
Exclusion not the key
The model on which ownership entails an owner with sole control over an asset, with the right to exclude all others from its use, is not adequate in my view to the concept of property.