I have a really hard time defining "tanking" in my own mind. Were the Red Sox tanking when they traded Lester and everyone else? Were the Timberwolves tanking when they traded Love? How about the 76ers when they traded Turner and everyone else?
I suspect that most would answer with at least one yes and maybe three. In terms of the Celtics, my definition of tanking would be losing or weakening your team on purpose with the primary goal of improving your draft position. By this definition, doing a trade of a veteran for young players (Love trade) would not necessarily be tanking, depending on your perspective.
I don't feel like the Celtics or Timberwolves are tanking but I do think the 76ers have been (I don't think they can tank anymore at this point, they don't have too, they are already bad enough).
So my euphemism, We are rebuilding, not 76'ing.