To be under the tutelage of another is to receive careful guidance and instruction from that person. A promising young violinist might be lucky enough to come under the tutelage of a world-renowned musician, receiving expert training and support in a manner that sets her up for future success. Tutelage comes from Latin tūtēla “guardianship,” and its earliest uses in English referred to the act of guarding or protecting, or to the office or function of a guardian. While the meaning of the term has broadened, it still suggests a degree of watchful protectiveness or personal interest on the part of the teacher or guide.
The adjective slow describes things characterized by a lack of speed (slow pace) or moving with less than usual speed (slow train). Sluggish, calling to mind everyone’s favorite shell-less gastropod, captures this as well. But sluggish also suggests a lack of activity, as in laziness or lethargy, or stagnant growth as in an industry or economy. You might feel sluggish after a grand feast, for instance. After your meal, perhaps while lounging about and browsing headlines, you might encounter news of sluggish sales in a retail sector or a sluggish economic recovery.
The noun device often refers to a smartphone or tablet, but if you're looking for more general term for brilliant doohickey or contraption, gadget is an excellent option. A gadget, properly defined, is a mechanical contrivance or device. It is the slightly more dignified cousin of such catchall terms as thingamajig, whatsit, and gizmo. Typically, the noun gadget implies some ingenuity and possible complexity. One might call something a gadget when one does not quite understand how it works but appreciates its utility.