Planetary scientists frequently refer to moons that are large enough to be in hydrostatic equilibrium as planets in the literature. Examples, just from a quick search:
"Locally enhanced precipitation organized by planetary-scale waves on Titan"
"3.3. Relevance to Other Planets" (section on Titan)
"Superrotation in Planetary Atmospheres" (article covers Titan alongside three other planets)
"All planets with substantial atmospheres (e.g., Earth, Venus, Mars, and Titan) have ionospheres which expand above the exobase"
"Clouds on Titan result from the condensation of methane and ethane and, as on other planets, are primarily structured by circulation of the atmosphere"
"... of the planet. However, rather than being scarred by volcanic features, Titan's surface is largely shaped..."
"Spectrophotometry of the Jovian Planets and Titan at 300- to 1000-nm Wavelength: The Methane Spectrum" (okay, it's mainly referring to the Jovian satellites as planets, but same point)
"Superrotation indices for Solar System and extrasolar atmospheres" - contains a table whose first column is "Planet", and has Titan in the list, alongside other planets
Etc. This is not to be confused with the phrase "minor planet", which is used for asteroids, etc. In general there's a big distinction in how commonly you see the large moons in hydrostatic equilibrium referred to as "planets" and with "planetary" adjectives, vs. smaller bodies not in hydrostatic equilibrium.