Trustworthy describes a person or thing you can trust and depend on. A trustworthy friend keeps your secret and does what they promised. A trustworthy website gives you facts you can check. The word is stronger and steadier than just "nice" or "kind" — it is about being reliable over time, not being pleasant once. It has a slightly formal, serious feel. In everyday talk people are more likely to say "you can trust him" or "he's reliable", while trustworthy shows up in writing: job references, school reports, news articles, book reviews. Notice that it works for people and for things that give you information — a trustworthy source, a trustworthy account of what happened, trustworthy figures. It works less well for machines; for those, English usually says reliable. There is a small difference worth knowing: reliable means it does the job every time; trustworthy adds the idea of honesty, of not deceiving you. A machine can be reliable but not trustworthy, because a machine cannot lie.