Step 1: Understanding the Concept:
Evaluating contextual meaning of prepositional phrasal verbs involving motion verbs.
Step 2: Detailed Explanation:
The phrasal verb 'to run into someone' figuratively means to encounter or meet an acquaintance unexpectedly or by chance (e.g., 'I ran into an old friend at the market').
Step 3: Final Answer:
Hence, 'Run into' means to meet by chance.