썸
ai5 meɪfɔː afɔːɹaɪmfɔːɹi ambɪɡjuːəs bʌt ɛssʌm spəsɪfɪkli dɪskɹaɪbz ðə pɹiːdeɪtɪŋ feɪz əvə ɹɪleɪʃənʃɪp
In Chinese 暧昧 (àimèi) - ambiguous, but 'ssum' specifically describes the pre-dating phase of a relationship.
A pre-dating stage of a romantic relationship, where two people are showing mutual interest and flirting, but are not yet officially dating.
Example
"그녀와 썸을 타고 있어요."