1. In a way that was not expected
   - out of the blue 
2. Without advance planning
   - by chance, accidentally, circumstantially

See also: unexpected

• haematinic
• haematite
• haemato-
• Haematobia
• Haematobia irritans
• haematocele
• haematochezia
• haematocoele
• haematocolpometra
• haematocolpos
• haematocrit
• haematocytopenia
• haematocyturia
• haematogenesis
• haematogenic
• haematohiston
• haematoidin
• haematological
• haematologist
• haematology
• haematolysis
• haematoma
• Haematopodidae
• haematopoiesis
• haematopoietic