Definitions of snug:

• noun:   a small secluded room
• adjective:   well and tightly constructed

  Example: "A snug house"

• adjective:   offering safety; well protected or concealed

  Example: "A snug harbor"

• adjective:   fitting closely but comfortably
• adjective:   enjoying or affording comforting warmth and shelter especially in a small space

  Example: "Snug in bed"