I found this record on the canadian census of 1901 http://www.bac-lac.gc.ca/eng/census/1901/Pages/results.aspx?k=cnsSurname%3a%22Kutschke%22+AND+cnsGivenName%3a%22Heinrich%22
It lists "William Kutschke" as "partner" of "Heinrich Kutschke". Looking at the age and the fact that they share the same last name makes me think he was rather the father, but i don't have further evidence as of now. Is there a meaning of the word "partner" here that i am missing?
The relationship "partner" in the Canada census of 1901 likely indicates "business partner", rather than the modern "in a relationship" usage.
An example of this is on this transcript of people from Newfoundland, where on page 37 Hugh McKenzie, 53, married with daughter, Hotel Keeper, has Alfred Ly??ley staying, described as "partner", age 27, occupation also Hotel Keeper. They both earn an identical amount from their occupation, so appear to be equal partners.
Here's another example (lines 11 to 15, household 4). Note how lodgers are described differently from the partner, and (unlike the previous example) there isn't a daughter that the person could be the partner of. Again the head is still married, making it unlikely to be some form of relationship.
Here's an example from the Yukon with many different partners, of varying ages. Again these are described separately from employees, and from a lodger. These are nearly all self-employed miners, with similar incomes.
So "business partner" does seem to be the meaning.
The instructions for enumerators (page 6) under item 48 says:
In column 6 the head of each family or household will be entered as such, and all others according to the relationship -- as wife, son, daughter, servant, boarder, lodger, partner, etc. The persons in an institution may be described as officer, inmate, patient, prisoner, pupil, etc.
Not much help there. Can you find other historical records that contain both people (e.g. newspapers) that might shed more light on the relationship? Do they appear in the same household in any other census years?
Note that the support materials for the 2011 Census at Statistics Canada, includes a Census Dictionary. The entry Census Family, notes that the definition of a census family has changed over time. There are several references to 'partners' referring to common-law marriages, and notes that "As of 2006, a married couple may be of opposite or same sex."
To answer definitively we would need to find similar materials that were produced at the time of the 1901 Census, or at least records closer in time to 1901.
The instructions for the 1920 US Federal Census are more explicit:
[section 101]. Family defined.-The word "family," for census purposes, has a somewhat different application from what it has in popular usage. It means a group of persons living together in the same dwelling place. The persons constituting this group may or may not be related by ties of kinship, but if they live together forming one household they should be considered as one family. Thus a servant who sleeps in the house or on the premises should be included with the members of the family for which he or she works. Again, a boarder or lodger should be included with the members of the family with which he lodges, but a persons who boards in one place and lodges or rooms at another should be returned as a member of the family at the place where he lodges or rooms.
[section 111]. If two or more persons share a common abode as partners, write head for one and partner for the other or others.
If the Canadian usage is the same, then in census-speak the "head" and "partner" could be what we call "roommates" today.
Maybe one is the business partner of the other?
