Similar words
decerto
decerto and seguramente are close synonyms for "surely," largely interchangeable.
Similar in other languages
German
sicherlich
Close — certainly/surely and sicherlich overlap.
English
certainly
Close — surely relates to certainly.
Practice
1 What does seguramente mean?
surely
2 Fill the gap: ___ ele sabe.
Full sentence: Seguramente ele sabe. (He surely knows.)
3 Which fingerprint chart matches seguramente?
seguramente: neutral register, common frequency, general domain, neutral connotation.